Parasitic leiomyoma with myxoid degeneration mimicking malignancy: A case report and review of literature

Alfa A Sule; Ibrahim B Sule; Mohammed A Gana; Amina L Abubakar; Aminu Magaji; Chijoke C Umelo; Ilyasu Garba

doi:10.4103/ais.ais_4_19

CASE REPORT

Year : 2019 | Volume : 9 | Issue : 1 | Page : 24-27

Parasitic leiomyoma with myxoid degeneration mimicking malignancy: A case report and review of literature

Alfa A Sule¹, Ibrahim B Sule², Mohammed A Gana², Amina L Abubakar², Aminu Magaji², Chijoke C Umelo², Ilyasu Garba³
¹ Department of Pathology, General Hospital, Minna, Nigeria
² Department of Obstetrics and Gynaecology, General Hospital, Minna, Nigeria
³ Department of Radiology, General Hospital, Minna, Nigeria

Date of Submission	09-Jan-2019
Date of Acceptance	01-Oct-2019
Date of Web Publication	16-Apr-2020

Correspondence Address:
Dr. Alfa A Sule
Department of Pathology, General Hospital, Minna
Nigeria

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/ais.ais_4_19

Abstract

Parasitic leiomyoma is a rare, benign smooth muscle tumor occurring in an extrauterine location. Their unusual growth pattern may mimic malignancy and, hence, could pose diagnostic and management challenges. Myxoid degeneration is further rarer finding in leiomyoma. There are few published cases of parasitic leiomyoma in our setting, hence, this report. A 52-year-old female presented with 4-year history of painless, progressive abdominal swelling with associated anorexia, weight loss, and body weakness. Abdominal examination revealed non-tender, nodular mass of 24 weeks size. Ultrasound scan showed a large well-defined heterogeneously hyperechoic right pelvic tumor crossing the midline. She had exploratory laparotomy; however, the histology confirmed parasitic leiomyoma with myxoid degeneration. Parasitic leiomyoma is an uncommon extrauterine benign tumor that mimics abdominopelvic malignancies. Meticulous clinical evaluation with radiologic and pathologic findings is the key to the otherwise challenging diagnosis.

Keywords: Myxoid degeneration, parasitic leiomyoma, tumor

How to cite this article:
Sule AA, Sule IB, Gana MA, Abubakar AL, Magaji A, Umelo CC, Garba I. Parasitic leiomyoma with myxoid degeneration mimicking malignancy: A case report and review of literature. Arch Int Surg 2019;9:24-7

How to cite this URL:
Sule AA, Sule IB, Gana MA, Abubakar AL, Magaji A, Umelo CC, Garba I. Parasitic leiomyoma with myxoid degeneration mimicking malignancy: A case report and review of literature. Arch Int Surg [serial online] 2019 [cited 2023 Dec 3];9:24-7. Available from: https://www.archintsurg.org/text.asp?2019/9/1/24/282579

Introduction

Leiomyoma is a benign smooth muscle tumor and it is the most common benign pelvic tumor affecting women of reproductive age group with an incidence of 20 to 30% in women older than 35 years. The size varies from microscopic to giant and could be intrauterine or extrauterine.^[1] Parasitic leiomyoma is a very rare extrauterine benign smooth muscle tumor that developed an auxiliary blood supply and lose their original attachment to the uterus, thus becoming parasitic. Their unusual growth pattern may mimic malignancy and pose diagnostic and management challenges. The etiology is unknown; however, iatrogenic causes following uterine myomectomy, especially when morcellators are used for retrieval or unintentional seeding of the fragments during the procedure, were suggested.^[2] Myxoid degeneration is also uncommon finding in leiomyoma.^[3] There are scanty published reports on parasitic leiomyoma with myxoid degeneration in sub-Saharan Africa, more so from Nigeria. Here, we are reporting a rare case of parasitic leiomyoma with myxoid degeneration.

Case Report

A 52-year-old female, para 8 with 7 living children and 3 years postmenopausal, presented with 4-year history of painless, progressive abdominal swelling with associated anorexia, weight loss, and body weakness. There was no history of vaginal or rectal bleeding, and no foul-smelling vaginal discharge. Abdominal examination revealed non-tender, nodular mass of 24 weeks size, can get above but not below it. Ultrasound scan showed a well-defined right-sided solid pelvic mass, which crosses the midline and measured 22 cm in diameter. The mass was closely related to the uterus, appear heterogeneously hyperechoic with irregular cystic component but no demonstrable vascular connection with the uterus, and was suspected to be a malignant pelvic tumor. No ascites or abdominal lymphadenopathy was seen. CA 125 was 12 mIU/mL and other biochemical investigations were essentially normal.

Exploratory laparotomy revealed a huge mass arising from the right iliac fossa, adherent to the ascending and transverse colon and the posterior wall of the uterine fundus; it measured about 25 × 20 cm and firm. Grossly, it was nodular with well-demarcated borders, measured 20 × 14 × 10 cm and weighed 1.3 kg; cut surface showed myxoid appearance with intervening grayish-white whorled surface. Histology revealed well-demarcated lesions composed of bundles of interlacing fascicles of spindle cells having elongated bland nuclei disposed within an edematous myxoid stroma. Diagnosis of parasitic leiomyoma with myxoid degeneration was made. She recovered fully postoperatively and was also seen at the Gynecology clinic for follow-up and has been clinically stable.

[Figure 1] and [Figure 2] show the photomicrograph of gross appearance and histology of leiomyoma with myxoid degeneration respectively.

Figure 1: Cut surface showing myxoid appearance

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Figure 2: Myxoid leiomyoma (H and E × 10)

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Discussion

Parasitic leiomyoma is a rare, benign smooth muscle tumor occurring in an extrauterine location.^[4] They can be found in pelvic peritoneum, omentum, cul-de-sac, and broad ligament.^[2] Pedunculated subserosal leiomyomas can be twisted on the uterine pedicle and lose their original attachment to the uterus, thus becoming “parasitic” survives by revascularization from adjacent structures which includes colon as observed in the index case, omentum, inferior mesenteric artery, and common iliac artery.^[5]

Several reports have also shown that parasitic leiomyomas are common following laparoscopic myomectomy, especially in those cases where tumors are morcellated for removal. Cucinella et al. conducted a retrospective study to show the development of parasitic leiomyoma after the application of a morcellator over three years, out of 423 patients who had morcellation, 0.9% developed parasitic leiomyoma.^[6] Kimberly et al. documented 12 cases of parasitic leiomyomas, 10 had previous abdominal surgery and 8 had morcellation procedures.^[7] Lu et al. reported six cases of parasitic leiomyoma, all of whom had the history of laparoscopic hysterectomy or myomectomy with power morcellation.^[8] It is noteworthy that the importance of inspection and thorough washing of abdominopelvic cavity after procedure cannot be overemphasized. The index case had no history of previous surgery as in most reported reviews. There are very few of such cases documented; Salih et al. reported parasitic leiomyoma in a 46-year-old female without history of prior abdominal procedure.^[9] Zaitoon reported a parasitic leiomyoma in a 40-year old morbidly obese female devoid of previous abdominopelvic surgery.^[10] Abdel-Gadir et al. also documented a 35-year-old female with secondary infertility with no past operation.^[11]

Furthermore, parasitic leiomyoma has the preponderance of occurrence in pelvic (93%).^[12] Ghamande et al. reported a 32-year old female with parasitic leiomyoma occurring in right para-rectal area displacing the right adnexa, appendix, and caecum anteromedially.^[13] The index case was found on the colon which is in accord with the report by Pezzuto et al.^[14] Parasitic leiomyomas are usually asymptomatic and at times may present with pressure symptoms such as abdominal swelling, discomfort, easy satiety, and nausea.^[15] These symptoms were observed in the current case.

When leiomyomas enlarge, they may outgrow their blood supply, resulting in various types of degeneration which includes hyaline, myxoid, calcification, fatty, cystic, and red degeneration. Hyaline degeneration is the most common and accounted for 60% of cases; the myxoid changes is an infrequent and composed of smooth muscle cells, with a large amount of a cellular material rich in acid mucins.^[16] The present case exhibits myxoid degeneration.

Radiologic studies are vital in making a diagnosis. In ultrasonography, degenerative leiomyoma is usually hypoechogenic and excessive degeneration may be recognized as a cystic pattern. In our case, ultrasound scan showed heterogeneous hyperechoic echo pattern with cystic component. The myxoid component is heterogeneous, high intensity on MRI T2 weighted images.^[17] The definitive diagnosis is by histological examination which also rules out malignancy. The distinction of myxoid leiomyoma from myxoid leiomyosarcoma is based on nuclear atypia, mitotic figure, and necrosis. Myxoid liposarcoma will in addition to atypical features show variable number of small lipoblasts.^[18] Immunohistochemistry is also useful in distinguishing them. In the index case, no atypical changes were seen.

Conclusion

Parasitic leiomyoma is an uncommon extrauterine benign tumor that mimics abdominopelvic malignancies. Meticulous observation of the patient's history, location of the mass, high index of suspicion, and radiologic and pathologic conclusions are the key to this challenging diagnosis.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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